• Annals of Clinical Neurophysiology
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• 제1권1호
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• pp.70-75
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• 1999

Trancranial Doppler(TCD) monitoring is a new application of ultrasonography which allows the nonivasive detection of blood flow velocity in the horizontal (M1) segment of the middle cerebral artery (MCA) and detects microembolic phenomena in the cerebral circulation. Recent studies emphasized the potential of using this technique in vascular surgery (carotid endarterectomy, cardiopulmonary bypass), interventional and intensive care setting. Although the disparity between CBF and blood flow velocity and number of microemboli could be used to prevent cerebral ischemic and embolism based on clinical studies. A reduction of more than 60% of MCA can reflex hemodynamic ischemic state and acoustic feedback of high intensity transient signals(HITS) from the TCD monitoring unit has a direct influence on surgical technique. TCD monitoring can immediately provide information about thromboembolism and hemodynamic changes, which may be a useful tool in the study and prevention of stroke.

• The Korean Journal of Pain
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• 제9권1호
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• pp.63-68
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• 1996

Background; Epidural analgesia for controlling labor pain has recently gained world-wide popularity. However, many patients scheduled for continuous epidural analgesia voice concern over harmful effects to their fetus and other possible complications such as hemodynamic changes, back pain and neurologic sequelae etc. The aim of this study was to evaluate the hemodynamic changes with and without epidural block as a measure to determine the safety of epidural analgesia during labor and delivery. Methods: Twenty healthy subjects were divided equally into two groups(Group 1 without epidural block, and Group 2 with epidural block) and serial hemodynamic measurements were taken in all subjects with transcutaneous impedence cardiography. The epidural catheter was inserted at the level of $L_{3,4}$ in Group 2 and analgesia was maintained using 0.25% bupivacaine mixed with fentanyl. Results: Cardiac output increased slightly with cervical dilatation in both groups, but no significant differences were found between the two groups. Similarly, no significant differences were found in blood pressures between the two groups. Stroke volume and end-diastolic volume indices were slightly decreased in group 1 and slightly increased in group 2. However, there were no significant differences between the two groups. The ejection fraction was nearly constant and ranging 56~59%. Conclusion: We concluded epidural analgesia for labor and delivery is a safe technique for the parturients since results indicated no significant differences in hemodynamic changes, as compared to the control group.

• 대한의용생체공학회:의공학회지
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• 제23권2호
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• pp.131-137
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• 2002

이동 작동기형 인공 심장의 원격 모니터링을 위한 시스템을 설계, 구현하였다 동물 실험이나 환자에의 임상 실험 후 인공 심장 동작 상황에 대한 원격 모니터링은 필수적이다. 본 논문에서는 담당자가 환자로부터 멀리 떨어진 곳에 있을 때에도 인터넷을 통해 간편하게 인공 심장의 동작 상황과 혈류역학 정보를 확인할 수 있는 시스템을 제안하여 그 성능을 확인하였다. 기존의 시스템과 쉽게 연결하여 사용할 수 있도록. 또 쉬운 관리와 기능 향상을 위하여 COM(Component Object Model) 기술 기반의 콤포넌트 모듈로 데이터 전송 부분을 구현하였고. 범용의 브라우저를 이용하여 인터넷에 연결, 확인토록 자바 애플릿을 이용하여 실행되도록 하였다. 또한 정해진 룰에 따라 판단하여 인공 심장의 이상 동작시 관리자에게 알려주도록 하였다. 구현된 시스템을 1개월 이상 생존하는 동물에 적용하여 본 결과 아무런 문제없이 정상 동작함을 확인하였다.

• Current Optics and Photonics
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• 제4권1호
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• pp.57-62
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• 2020

The selection of anesthetic agent is important in preclinical studies, since each agent affects the systemic hemodynamics in different ways. For that reason, we hypothesized that different anesthetic agents will result in different vaginal hemodynamic response and temperature during sexual arousal, in an animal model. To validate the hypothesis, animal experiments were performed using female rats with two anesthetic agents widely used in preclinical studies: ketamine and isoflurane. Our previously developed near-infrared-spectroscopy-based probe was used to measure the changes of oxyhemoglobin (OHb), deoxyhemoglobin (RHb), and total hemoglobin (THb) concentrations along with temperature from the animal vaginal wall. As a control, saline was administered to both isoflurane- and ketamine-anesthetized animals, and did not show any significant changes in OHb, RHb, THb, or temperature. However, an administration of apomorphine (APO, 80 ㎍/kg) induced increases of OHb (63 ± 28 μM/DPF), RHb (35 ± 20 μM/DPF), and THb (98 ± 49 μM/DPF) in ketamine-anesthetized animals, while decreases of OHb (52 ± 76 μM/DPF) and THb (38 ± 30 μM/DPF) and an increase of RHb (28 ± 51 μM/DPF) were found in isoflurane-anesthetized animals. The vaginal temperature decreased from the baseline in both ketamine-(0.42℃) and isoflurane-(1.22℃)anesthetized animals. These results confirmed our hypothesis, and suggest that a preclinical study monitoring hemodynamic responses under anesthesia should employ an appropriate anesthetic agent for the study.

• 대한핵의학회지
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• 제8권1_2호
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• pp.1-11
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• 1974

The author in an attempt to evaluate hemodynamic changes in the clinical stages of Korean hemorrhagic fever measured plasma volume, cardiac output and effective renal plasma flow utilizing radioisoto es during various phases of the disease. Cardiac output was measured by radiocardiography with external monitoring method using RIHSA. Effective renal plasma flow was obtained from blood clearance curve drawn by external monitoring after radiohippuran injection according to the method described by Razzak et al. The study was carried out in thirty-eight cases of Korean hemorrhagic fever and the following conclusions were obtained. 1. Plasma volume was increased in the patients during the oliguric-and hypertensive diuretic phases, while it was normal in the patients during the normotensive-diuretic phase. 2. Cardiac index was increased in the patients during the oliguric phase and was slightly increased in the patients at the hypertensive diuretic phase. It was normal in the other phases. 3. Total peripheral resistance was increased in the hypertensive patients during diuretic phase, while it was normal in the rest of phases. 4. Effective renal plasma flow was significantly reduced in the patients during the oliguric and diuretic phases as well as at one month after the oliguric onset. There was no significant difference between the oliguric and the early diuretic phases. Renal plasma flow in the group of patients at one month after the oliguric onset was about 45% of the normal, however, it returned to normal level at six months after the onset. 5. Clinical syndrome of relative hypervolemia was observed in some patients during the oliguric phase or hypertensive diuretic phase. Characteristic hemodynamic findings were high cardiac output and normal to relatively increased peripheral resistance in these cases. Relatively increased circulating blood volume due to decreased effective vascular space was suggested for the mechanism of relative hypervolemia. 6. Cardiac hemodynamic alteration returned to normal during late stage of the diuretic phase, while renal hemodynamic changes were normalized at six months after the onset.

• 대한신경과학회지
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• 제35권1호
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• pp.8-15
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• 2017

Near-infrared spectroscopy (NIRS), a noninvasive optical method, utilizes the characteristic absorption spectra of hemoglobin in the near-infrared range to provide information on cerebral hemodynamic changes in various clinical situations. NIRS monitoring have been used mainly to detect reduced perfusion of the brain during orthostatic stress for three common forms of orthostatic intolerance (OI); orthostatic hypotension, neurally mediated syncope, and postural orthostatic tachycardia syndrome. Autonomic function testing is an important diagnostic test to assess their autonomic nervous systems for patients with symptom of OI. However, these techniques cannot measure dynamic changes in cerebral blood flow. There are many experimentations about study of NIRS to reveal the pathophysiology of patients with OI. Research using NIRS in other neurologic diseases (stroke, epilepsy and migraine) are ongoing. NIRS have been experimentally used in all stages of stroke and may complement the established diagnostic and monitoring tools. NIRS also provide pathophysiological approach during rehabilitation and secondary prevention of stroke. The hemodynamic response to seizure has long been a topic for discussion in association with the neuronal damage resulting from convulsion. One critical issue when unpredictable events are to be detected is how continuous NIRS data are analyzed. Besides, NIRS studies targeting pathophysiological aspects of migraine may contribute to a deeper understanding of mechanisms relating to aura of migraine. NIRS monitoring may play an important role to trend regional hemodynamic distribution of flow in real time and also highlights the pathophysiology and management of not only patients with OI symptoms but also those with various neurologic diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제42권5호
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• pp.295-300
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• 2016

Submucosal infiltration and the topical application of epinephrine as a vasoconstrictor produce excellent hemostasis during surgery. The hemodynamic effects of epinephrine have been documented in numerous studies. However, its metabolic effects (especially during surgery) have been seldom recognized clinically. We report two cases of significant metabolic effects (including lactic acidosis and hyperglycemia) as well as hemodynamic effects in healthy patients undergoing orthognathic surgery with general anesthesia. Epinephrine can induce glycolysis and pyruvate generation, which result in lactic acidosis, via ${\beta}2$-adrenergic receptors. Therefore, careful perioperative observation for changes in plasma lactate and glucose levels along with intensive monitoring of vital signs should be carried out when epinephrine is excessively used as a vasoconstrictor during surgery.

• Journal of Chest Surgery
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• 제55권4호
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• pp.325-331
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• 2022

Postoperative critical care management for lung transplant recipients in the intensive care unit (ICU) has expanded in recent years due to its complexity and impact on clinical outcomes. The practical aspects of post-transplant critical care management, especially regarding ventilation and hemodynamic management during the early postoperative period in the ICU, are discussed in this brief review. Monitoring in the ICU provides information on the patient's clinical status, diagnostic assessment of complications, and future management plans since lung transplantation involves unique pathophysiological conditions and risk factors for complications. After lung transplantation, the grafts should be appropriately ventilated with lung protective strategies to prevent ventilator-induced lung injury, as well as to promote graft function and maintain adequate gas exchange. Hypotension and varying degrees of pulmonary edema are common in the immediate postoperative lung transplantation setting. Ventricular dysfunction in lung transplant recipients should also be considered. Therefore, adequate volume and hemodynamic management with vasoactive agents based on their physiological effects and patient response are critical in the early postoperative lung transplantation period. Integrated management provided by a professional multidisciplinary team is essential for the critical care management of lung transplant recipients in the ICU.

• Journal of Chest Surgery
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• 제22권2호
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• pp.212-219
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• 1989

We utilized pulmonary artery pressure monitoring system in risky patients for preventing the postoperative pulmonary hypertensive crisis and for sampling the mixed venous blood. And this mixed venous blood oxygen saturation [MVSO2] or partial pressure [MVPO2]tells us many meaningful patients state. We selected 59 cyanotic congenital heart diseased patients, who were operated in our hospital from Nov. 1987 to Oct. 1988, in the Department of Thoracic and Cardiovascular Surgery, Seoul National University Children\ulcorner Hospital, who had pulmonary artery pressure monitoring catheter and who made us know their mixed venous oxygen condition. We found that there was no close relationship between MVPO2 and Cardiac Index [C.I.] during early postoperative period, but on the first and second day after operation the correlation coefficient was increased as r=0.35[p=0.008], r=0.78[p=0.0001]. So we concluded that the correlation between MVPO2 and C.I. was more reliable with time going as hemodynamic stabilization. And we experienced no survivors whose MVPO2 was under 20 torr, but that was not the only factor for death. From these results, we conclude that we can consider the MVPO2 [or MVSO2] representing C.I. after stabilized postoperative condition of the open heart surgery patients, but during early postoperative period, in addition to this MVPO2, we should do also apply other parameter such as urine output, arterial blood pressure, left atrial pressure and pulmonary arterial pressure for exact estimation of the patients status.

• Annals of Clinical Neurophysiology
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• 제20권2호
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• pp.57-65
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• 2018

Near-infrared spectroscopy (NIRS) monitoring has been used mainly to detect reduced perfusion of the brain during orthostatic stress in order to assess orthostatic intolerance (OI). Many studies have investigated the use of NIRS to reveal the pathophysiology of patients with OI. Research using NIRS in other neurological diseases (e.g., stroke, epilepsy, and migraine) is continuing. NIRS may play an important role in monitoring the regional distribution of the hemodynamic flow in real time and thereby reveal the underlying pathophysiology and facilitate the management of not only patients with OI symptoms but also those with various neurological diseases.